Quantitative Precipitation Forecast
Issued by NWS

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000
FXUS04 KWBC 230700
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
259 AM EDT THU OCT 23 2014


PRELIM DAY 1 QPF DISCUSSION
VALID OCT 23/1200 UTC THRU OCT 24/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

18z UPDATE...
BASED ON SATL/RADAR TRENDS AS WELL AS 18Z MODEL TRENDS HAVE
SHIFTED HEAVIER PCPN AMOUNTS SWD A BIT ACRS SRN NEW ENGLAND AS LOW
PRES CONTINUES TO GET BETTER ORGANIZED AND LOOPING SOUTH OF LONG
ISLAND.  ALSO SLOWED EWD PROGRESS OF FRONTAL BAND PCPN ACRS THE
CNTL U.S. IN LINE WITH RADAR TRENDS AND MULTI MODEL CONSENSUS.

...PACIFIC NORTHWEST INTO NORTHWEST CALIFORNIA...

NO SIGNIFICANT CHANGES TO THE PREVIOUS THINKING. THE LATEST
BLENDED TPW/GOES-SOUNDER IMAGERY SHOWS A WELL DEFINED PLUME OF
HIGHER PWATS STRETCHING ACROSS THE CENTRAL AND EASTERN PACIFIC
OCEAN AND INTO THE PACIFIC NORTHWEST ALONG AND AHEAD OF A SURFACE
COLD FRONT WHICH IS AGAIN EXPECTED TO SINK SLOWLY SOUTHEASTWARD
ACROSS THE NORTHWEST THIS PERIOD. STRONG ONSHORE SOUTH
SOUTHWESTERLY FLOW WITHIN THE DEEPER PACIFIC MOISTURE PLUME WILL
CONTINUE TO FOSTER HEAVY RAINFALL AMOUNTS FOR THE OROGRAPHICALLY
FAVORED COASTAL RANGES AND THE CASCADES. THE HEAVIER RAINS SHOULD
BEGIN TO SETTLE AS FAR SOUTH AS COASTAL AREAS OF NORTHWEST CA BY
LATER TONIGHT AND ESP ON THURSDAY. THE MODELS ARE IN GOOD
AGREEMENT WITH THE LARGER SCALE SET-UP FOR HEAVY RAIN...AND WPC
LEANED TOWARD A GENERAL MODEL CONSENSUS...WITH AMOUNTS ENHANCED
LOCALLY TO ACCOUNT FOR TOPOGRAPHY AND IN ACCORDANCE WITH THE 12Z
ARW AND 12Z NMMB SOLUTIONS. THIS MEANS FAIRLY WIDESPREAD RAINFALL
AMOUNTS OF 2 TO 4 INCHES...WITH THE HEAVIEST TOTALS ACROSS THE OR
CASCADES AND INTO THE SOUTHWEST OR/NORTHWEST CA COASTAL RANGES.


...EASTERN PORTIONS OF THE CENTRAL TO NORTHERN PLAINS INTO THE
UPPER MS VALLEY...

THE MODELS ARE IN REASONABLY GOOD AGREEMENT WITH THE EASTWARD
ADVANCE OF A SHORTWAVE TROUGH OUT ACROSS THE NORTHERN/CENTRAL
PLAINS AND INTO THE UPPER MS VALLEY THROUGH THURS. INCREASINGLY
SOUTHERLY FLOW AND MOISTURE TRANSPORT AHEAD OF THE ASSOCIATED COLD
FRONT LATER TODAY AND TONIGHT WILL FOSTER A N/S ORIENTED BAND OF
BROKEN CONVECTION...AND ESPECIALLY IN CONCERT WITH AN UPTICK IN
SURFACE-BASED INSTABILITY. HOWEVER...THE MODELS STRONGLY SUPPORT
THIS FRONT WEAKENING ON THURSDAY AS IT MOVES INTO THE MS
VALLEY...WITH A DECREASE IN LOW LEVEL SOUTHERLY FLOW AHEAD OF IT.
SO...CONVECTION WITH THIS SYSTEM SHOULD BECOME CONSIDERABLY
DISORGANIZED AND MORE LIMITED ON THURSDAY. WPC GENERALLY FAVORED A
BLEND OF THE 12Z GFS AND THE 00Z ECMWF.


...SOUTH FLORIDA...

A VERY STRONG MOISTURE GRADIENT IS SITUATED OVER SOUTH FL IN
PROXIMITY TO A FRONTAL ZONE DRAPED W/E ACROSS THE AREA. VERY DEEP
TROPICAL MOISTURE IS POOLED OVER THE SOUTHEAST GULF OF MEXICO AND
THE NORTHWEST CARIBBEAN SEA WITH SOME OF THIS FOCUSED EAST ACROSS
THE FL KEYS. NUMEROUS SHWRS/TSTMS ARE EXPECTED TO BE FOCUSED AGAIN
THROUGH THURSDAY ALONG AND SOUTH OF THE AFOREMENTIONED FRONT. THE
BEST ORGANIZATION SHOULD TEND TO BE FARTHER SOUTH CLOSER TO CUBA
AND THE ADJACENT NORTHWEST CARIBBEAN SEA...BUT THERE MAY BE SOME
LOCALLY HEAVY RAINFALL AMOUNTS ON THE ORDER OF A COUPLE OF INCHES
GIVEN THE EXPECTED INTENSE RAINFALL RATES.


...NEW ENGLAND...

THE CLOSED LOW INITIALLY OVER THE MID ATLANTIC WILL BE SWINGING
SLOWLY NORTHEASTWARD OFF THE NORTHERN MID ATLANTIC COAST AND
TOWARD SOUTHERN NEW ENGLAND THIS PERIOD. PERSISTENT AND STRONG
ONSHORE EASTERLY FLOW TO THE NORTH AND EAST OF THIS MID TO UPPER
LEVEL CLOSED LOW WILL MAINTAIN WET CONDITIONS FROM THE COASTAL
MID-ATLANTIC NORTHWARD INTO NEW ENGLAND...WITH MUCH OF NEW ENGLAND
EXPECTED TO SEE A SIGNIFICANT EXPANSION OF MODERATE TO HEAVY
RAINFALL LATER TONIGHT AND THROUGH THURSDAY. THE 12Z GFS AND 00Z
ECMWF SUGGEST A DEEP ATLANTIC FETCH OF MOISTURE...WITH H85
MOISTURE TRANSPORT FORECAST TO REACH 3 TO 4 STD DEV ABOVE NORMAL
BY EARLY THURSDAY OVER MUCH NORTHERN NEW ENGLAND. ALL THE
WHILE...A ROBUST MID TO UPPER LEVEL DEFORMATION ZONE IS FORECAST
TO SET UP OVER THE REGION GIVEN PROXIMITY OF THE CLOSED LOW. THE
GLOBAL MODELS LED BY THE GFS AND ECMWF SUGGEST THE HEAVIEST
RAINFALL AMOUNTS FOCUSING OVER CENTRAL/EASTERN ME...WITH THE
HI-RES GUIDANCE...INCLUDING THE 12Z NAM-CONEST...12Z ARW AND 12Z
NMMB FAVORING SOMEWHAT HEAVIER TOTALS A LITTLE FARTHER SOUTH OVER
SOUTHERN ME AND INTO COASTAL AREAS OF EASTERN MA AND NH. WPC QPF
FAVORED A BLENDED APPROACH BETWEEN CAMPS AT THIS TIME GIVEN THE
TROUBLE THE LATEST GUIDANCE APPEARS TO BE HAVING IN HANDLING THE
QPF DETAILS OVER THE MID-ATLANTIC REGION. IN ANY CASE...HEAVY
RAINFALL AMOUNTS ARE EXPECTED...WITH WPC FAVORING 2 TO 4 INCH
RAINFALL AMOUNTS WITH ISOLATED HEAVIER TOTALS GIVEN SUCH A STRONG
LOW LEVEL JET FORECAST TO COME IN OFF THE ATLANTIC OCEAN. SOME
RUNOFF PROBLEMS WILL BE POSSIBLE AT LEAST LOCALLY.

ORRISON

GRAPHICS AVAILABLE ON THE WEB AT WWW.WPC.NCEP.NOAA.GOV

24HR QP VT 24/12Z
 0.01 413659 419635 431622 452609 473604 482617 491651 492669
      491679 489690 486703 484712 478731 474740 470744 467746
      462751 453755 441758 438761 436765 433767 429768 419769
      415767 411763 409759 408754 408748 409744 411740 412735
      411731 405729 397731 389729 383722 375717 373714 372708
      374700 377691 382683 387676 394671 398669 401671 404675
      404681 404684 405686 407690 410692 412694 414692 418684
      418671 413659
 0.01 531194 530179 528172 525166 522160 517153 510145 493129
      488126 481124 473122 467121 448133 438136 433140 430145
      426149 423155 421162 419171 415177 413184 410190 406195
      399202 394207 391213 388219 383223 379227 377235 378241
      381246 384253 389257 389264 394269 398272 404271 423261
      428260 433257 445256 455262 465270 476279 481283 487286
      492288 497292 508293 513272 517268 519260 522244 520236
      517231 515223 516218 519216 523216 527211 531194
 0.01 522918 521910 518902 515895 511890 506885 505883 505879
      504872 501867 496863 505854 505844 501838 496834 492833
      489832 484831 477832 450842 446842 444841 440841 438839
      429829 424824 418824 415823 411824 406829 405831 405836
      404845 401854 398860 390869 386875 384882 386884 388884
      395879 398878 398882 397885 393900 392909 387914 382918
      376923 366931 361934 359939 353954 352957 352962 356968
      359972 366972 386955 395947 407940 418934 431928 438926
      446923 452922 459921 464919 471918 479917 487918 492922
      499926 503929 510930 514929 518925 522918
 0.01 449210 448208 447208 446209 448210 449210
 0.01 451105 453100 451097 448097 446098 443098 439097 437098
      437102 437107 437110 440110 443111 445109 447109 449107
      451105
 0.01 278059 284059 294043 289037 286040 284038 289030 289023
      281015 278014 274012 271008 267006 262999 259996 254994
      245991 242993 240997 243006 243013 244018 249025 253028
      255029 261028 267028 272030 275034 281040 276046 274050
      275055 278059
 0.01 268796 268789 267781 265774 262770 258768 253766 245767
      240769 236772 234777 230787 227798 224809 219831 220846
      220853 222859 224865 227869 232871 237870 241867 245863
      248858 250853 252842 256830 257825 260821 264816 266810
      266802 268796
 0.25 426662 427650 427636 441621 459613 468610 475620 480639
      482650 483659 483669 482679 479699 475715 471722 467729
      463734 457739 450744 445747 432756 427756 421752 419750
      418747 422740 424731 425727 425722 421718 413717 396720
      390718 388713 388708 388704 392701 396700 397703 403705
      408704 412702 422690 426685 428681 428676 426662
 0.25 523195 523185 522175 518166 513159 507154 500149 495144
      491137 485132 477130 463137 457141 454144 451146 443145
      440143 437144 434152 433158 435161 439167 444177 441181
      438184 432188 427194 425197 421199 416201 410206 408208
      404210 400210 398213 397219 395224 389227 385235 385239
      387245 391250 399250 414248 422246 425244 428240 430236
      433235 437237 439241 444247 450250 469257 476261 479264
      484266 492270 496272 501272 509262 511255 512248 511237
      507229 504219 501212 498208 495207 490203 484204 469209
      462210 454213 447215 442215 434211 432208 433203 434198
      436195 440194 444191 449190 455187 460183 463181 463174
      459173 460170 462168 465170 469172 473173 477175 480178
      482183 486186 491186 495188 502192 508196 512199 518200
      522197 523195
 0.25 482150 481149 479148 478148 477149 478150 479150 481152
      482150
 0.25 448908 449904 449899 444896 438896 432898 420902 415905
      412908 403916 398920 394924 393926 394930 400931 410926
      421922 431917 441913 446911 448908
 0.25 263798 263794 262789 257784 254777 249772 243773 238779
      235785 234792 231808 230816 229824 232832 235840 239840
      243840 246839 250833 252826 254818 256810 260805 263798
 0.50 430639 439630 451621 463615 469619 475633 477668 477686
      474700 472705 468711 463722 460726 455731 446739 438746
      432749 428749 426746 428739 429731 431727 431719 428713
      423711 419708 420703 421701 429691 431686 431677 430661
      431654 431649 430644 430639
 0.50 518183 517177 515171 511166 508163 503162 498162 492161
      488159 471151 465144 461144 457149 455152 450153 441151
      439152 438156 440162 446170 449175 451177 454177 453172
      454166 456164 461161 463160 466161 469165 473167 479168
      487175 492178 496179 506185 514188 517185 518183
 0.50 507253 508246 508239 506234 503231 500220 498215 494211
      490209 484208 479210 476212 473215 469216 459215 456217
      451219 443222 439224 440227 448224 451224 455227 454231
      452232 449234 446238 447241 452244 457246 466250 476255
      479257 485260 489260 492261 497263 500261 504257 507253
      507253
 0.50 491142 490140 490139 489138 487137 486136 484136 482138
      483140 483141 485142 487143 488144 489144 490144 491142
 0.50 461178 461177 459177 457177 456179 457181 459180 461179
      461178
 0.50 425234 427228 426222 422219 420220 418220 417218 414214
      410215 405214 403216 403221 401225 398227 391232 389238
      391243 394246 400246 407245 415243 422240 425234
 0.50 403711 403710 401709 399708 397708 396708 395708 394707
      393708 392709 391711 393713 394715 395715 397716 399716
      400716 402715 403713 403711 403711
 0.50 259797 258791 256787 248781 242782 239786 237798 234807
      232818 236829 238833 242835 246833 248829 251818 254808
      259799 259797
 1.00 472660 472654 471647 468641 466642 464643 461640 457638
      455641 454647 451646 444642 442641 438644 435652 435663
      436676 435686 433694 432699 433702 440706 443713 448713
      453711 465701 470695 472690 472685 470672 470666 472661
      472660
 1.00 409237 410230 412224 410221 408225 409230 406232 401231
      397233 394238 397242 402243 406241 408238 409237
 1.00 253802 253797 251792 249790 245790 242796 240803 238810
      237815 237820 240828 242831 243831 246823 248815 249808
      253802
 1.50 467684 465674 463663 461662 461671 458678 454671 446662
      442656 439657 440662 444681 443689 439690 436696 435698
      437700 442696 445700 452693 455695 458695 464690 467684
 1.50 249804 249798 246796 244799 241803 240807 239811 239817
      239823 241829 243829 244823 245819 246815 247809 248805
      249804
 2.00 247804 248800 246798 244800 243802 242805 241807 240811
      240813 240817 241821 243823 243819 244817 245813 245810
      246807 247804

$$





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